[Ffmpeg-devel] PIX_FMT_RGB555 and alpha channel

[Diego Biurrun]

On Mon, Oct 30, 2006 at 02:48:06AM +0100, Alex Beregszaszi wrote:
> 
> > > I will elaborate.  Alex and I are implementing FLC/FLX and DTA
> > > encoding  into ffmpeg.  We are a little way from having stuff ready
> > > to submit, but  there is a problem with compression when the Alpha
> > > bit is set in an  RGB555 pixel, for the FLX format.  It means we
> > > have to mask every pixel  coming in, to take the spurious alpha bit
> > > out, or that bit prevents run  length compression from being
> > > effective.  The format is really wanting  to use RGB555, without
> > > alpha, so that black is 0x0000 and not 0x8000 but 
> > 
> > why does RLE compression not work with the alpha bit set?
> > and why exactly is the alpha bit set at all? if imgconvert.c sets it,
> > IMO fix imgconvert.c so it doesnt
> 
> Attached is a patch which fixes it, and adds the old behaviour as
> RGBA555.

Your patch is full of tabs and trailing whitespace...

Diego